Rats, like humans, prefer flavors that have been associated with the rewarding properties of carbohydrates. Recent research has demonstrated the involvement of two parallel learning systems: an appetitive system mediating orienting and approach to preferred flavors, and a consummatory system mediating the vigor of intake once a stimulus has been contacted. However, it is now known whether these two processes play a role in appetite for fats. Also, the physiological and psychopharmacological bases for the separation between these two systems have not yet been explored. The proposed research will first evaluate appetitive and consummatory responses to flavors that have been associated with the putative oral or post-ingestive rewarding properties of fats, and will identify and describe the peripheral signals mediating these reward properties. Finally, these research will focus on the dissociation between appetitive and consummatory motivational systems at the pharmacological level. Although it is expected that appetite and preferences for flavors that act as cues for fat may share some fundamental properties with appetite carbohydrates, it is expected that there will be unique physiological and neural control systems involved. This research combining behavioral analysis, gut physiology, and psychopharmacology, is planned to contribute to a comprehensive understanding of the basic mechanisms underlying ingestive motivation, and will have value in efforts to manage and control unhealthy dietary habits.